Rock drill



C. 29, 1935. F M, SLATER 2,019,163

Y ROCK DRILL Filed NOV. 22, 1934 HIS A TTORNEY.`

Patented Oct. 29, 1935 UNETED STATES PATENT GFFEQE ROCK DRILL Fred M.Slater, Easton, Pa., assignor to Ingersoll- Rand Company, Jersey City,N. J., a corporation of New Jersey One object of the invention is tocontrol the rotative movement of the working implement in a simplifiedand improved manner.

Another object is to reduce the number of parts of the mechanismemployed for effecting rotation of the working implement.

Still another object is to employ the distributing Valve as a means forcontrolling the period of rotation of the working implement.

Other objects will be in part obvious and in r' part pointed outhereinafter.

In the drawing accompanying this specification and in which similarreference numerals refer to similar parts,

Figure 1 is a sectional elevation of a rock drill equipped with rotationmechanism constructed in accordance with the practice of the inventionand showing the parts in the positions which they will occupy at thebeginning of the working stroke of the piston, and

Figure 2 is a similar View showing the rifle bar restrained againstrotation and in consequence of which the piston describes a partialrevolution for rotating the working implement during the return strokeof the piston.

Referring more particularly to the drawing, 20 designates a rock drillcomprising a cylinder 2 I, a front cylinder washer 22 and front and backheads 23 and 24, respectively. 'I'hese parts constitute the casing ofthe rock drill and may be held in correct assembled relationship withrespect to each other in any known manner, for example side bolts (notsho-wn) and which may be disposed on diametrically opposite sides of thedrill, as is customary.

Within the cylinder 2l is a piston chamber 25 having a free exhaust port26 which is controlled by a piston 21 in the piston chamber 25. Thefront cylinder washer 22 serves as a closure for the front end of thepiston chamber and is bored to serve as a guide for a stem 28 on thefront end of the piston 21. The forward portion of the stem 28 isprovided with longitudinal ribs 29 which interlock with ribs 33 in achuck 3l arranged within the front head 23 to rotate therein. The chuck3| is provided with a suitable aperture 32 to receive and interlockinglyengage a working implement 33 against which the piston 21 strikes.

In the rearward portion of the piston 21 is a nut 34 which may be flutedto interlockingly engage a rifle bar 35 whereby rotation of the piston,the chuck 3| and the working implement 33 is effected. The rifle bar 35is journalled in a plate 36 which forms a closure for the rear end ofthe piston chamber' 35 and is seated in the bottom of an enlarged cavity31 in the cylinder 2 l The cavity 31 also contains valve mechanismdesignated, in its entirety, by 38 and comprising a valve chest 39 whichseats upon the plate 36 and y has a valve chamber 40 for theaccommodation 3 of a valve 4I whereby the pressure fluid is distributedto the ends of the piston chamber Z5. The plate 36 and the valve chest39 are clamped in the correct assembled positions by the back head 24 ofwhich the front end extends into the T5 cavity 31 and acts against thevalve chest 39.

'I'he valve 4l, selected for the purpose of illustration, comprises ahollow sleeve-like portion 42 of which the periphery engages slidablythe rearward portion of the valve chamber 40. Near the front end of thevalve is a flange 43 which controls the admission of pressure fluid tothe ends of the piston chamber through front and rear inlet passages 44and 45, respectively. The inlet passage 44 communicates with the Valvechamber 40 at a point rearwardly of the flange 43 and the inlet passage45 opens into a valve chamber at a point forwardly of the flange 43.

The admission of pressure fluid into the drill 30 is controlled by athrottle valve 4G in the back head 24 and having al central chamber 41which may be in constant communication with a source of pressure fluidsupply. In the wall of the throttle valve is a port 48 adapted toregister with a 35 supply passage 4S opening into the valve chamber 40through ports 50 and 5I and which may be in the form of annular grooveslying rearwardly and forwardly of the portion of the valve chambercontaining the flange 43 and communicating 40 with said portion.

On the front and rear ends of the flange 43 are bevelled surfaces whichconstitute actuating surfaces 52 and 53, respectively, and saidactuating surfaces are exposed directly to the pres- 45 sure uid withinthe ports 5i! and 5 l. The portion of the rear end of the flange 43encircled by the actuating surface 53 serves as a holding surface 54against which pressure fluid acts to hold the valve 4l in its foremostlimiting position during the admission of pressure fluid to the frontend of the piston chamber. Likewise, the portion of the front end of theflange encircled by the actuating surface 52 constitutes a holdingsurface 55 55 against which the pressure fluid flowing to the inletpassage 55 acts for holding the valve in the rearmost limiting position.

The holding surface 55 extends over the entire front end of the valveand may be interrupted only by an aperture 56 of polygonal form and intowhich extends a stem 51 carried, in this instance by the back head 24 torestrain the valve 4| against rotary movement.

In addition to its function of distributing the pressure uid to thepiston chamber the valveY 4I also serves to control the rotary movementof the piston 2l and interengaged parts. The valve is accordinglyprovided on its front end with a series of clutch teeth 53 to engagesimilar clutch teeth 59 on the rear end of the rie bar 31. Morespecifically, the clutch teeth 59 are arranged on a head 66 carried bythe rifle bar 35 and extending into the front end of the valve chamber40. 'Ihe rear portion of the head 50 is journalled in the front end ofthe valve chest 39, andion the forward end of the head 6U is a lateralflange 6| which lies within a recess 62 in the plate 36 and seatsagainst the valve chest 39 to hold the rie bar 35 against endwisemovement.

The operation of the device is as follows: With the valve 4| in the rearposition pressure fluid flows through the port 5l over the actuatingsurface 52 and the holding surface 55 through the inlet port 45 into therear end of the piston chamber. During this time the valve is held inthe rear end of the valve chamber by the pressure fluid and the clutchmembers 58 are out of engagement with the clutch members 59. The riflebar 35 is then free to rotate with respect to the valve.

The pressure fluid admitted into the rear end of the piston chamberdrives the piston 27 forwardly against the working implement 33. As thepiston proceeds forwardly it uncovers the exhaust port 26 and thepressure fluid employed for motivating it passes to the atmosphere.After the piston covers the exhaust port 26 the air in the front end ofthe piston chamber is compressed and flows through the inlet passage 44against the surface 54 to assist the pressure fluid acting against theactuating surface 53 in throwing the valve forwardly for cutting off theflow of pressure fluid to the rear end of the piston chamber.

In the new position of the valve the clutch teeth 58 engage the clutchteeth 59 of' the rie bar and the rifle bar will then be rmly heldagainst rotary movement. During its rearward stroke the piston will,therefore, describe a partial revolution and shift the working implementto a new position preparatory to the delivery of a subsequent blow tothe working implement.

When the piston covers the exhaust port 26, during the rearward stroke,the air entrapped in the rear end of the piston chamber is compressedand expelled through the inlet passage 45 against the surface 55 toassist the pressure fluid acting against the actuating area 52 inthrowing the valve rearwardly. When the front end of the piston uncoversthe exhaust port 26 the pressure fluid in the front end of the: pistonchamber is exhausted to the atmosphere and the valve is then shiftedrearwardly to again admit pressure fluid into the rear end of the pistonchamber and to disengage the clutch teeth 58 from the clutch teeth 59,thus completing the cycle of operation.

I claim:

1. In a fluid actuated rock drill, the combination of a casing having apiston chamber and a reciprocatory piston in the piston chamber, a riflebar interlockingly engaging the piston and being freely rotatable withrespect toI the casing, and a non-rotatable reciprocatory valve for 5distributing pressure fluid to the piston chamb-er, and means shiftedinto engagement with the rie bar by the valve to hold the rifle barstationary for effecting a partial revolution of the piston. l0

2. In a fluid actuated rock drill, the combination of a casing having apiston chamber and a reciprocatory piston in the piston chamber, a

'rifle bar interlockingly engaging the piston and being freely rotatablewith respect to the casing, 15 and a non-rotatable valve todistributepressure fluid to the piston chamber and to intermittently engage therifle bar to hold the rie bar stationary during one stroke of thepiston, thereby causing the piston to describe a partial revolution. 20

3. In a fluid actuated rock drill, the combination of a casing having apiston `chamber and a reciprocatory piston in the piston chamber, arifle bar interlockingly engaging the piston and being freely rotatablewith respect to the casing, 25 a valve for distributing pressure fluidto the piston chamber, means for preventing rotary movement of thevalve, and means on the valve to engage the rifle bar for holding saidrifle bar stationary and thereby cause the piston to de- 30 scribe apartial revolution.

4. In a fluid actuated rock drill, the combination of a casing having apiston chamber and a reciprocatory piston in the piston chamber, a riflebar interlockingly engaging the piston and 35 being freely rotatablewith respect to the casing,

a valve for distributing pressure fluid to the piston chamber, means forpreventing rotary movement of the valve, and clutch members on the valveand the rifie bar intermittently engaging each 40 other to hold therifle bar stationary and thereby cause the piston to describe a partialrevolution.

5. In a fluid actuated rock drill, the combination of a casing having apiston chamber and a reciprocatory piston in the piston chamber, a 45rifle bar interlockingly engaging the piston and being rotatable withrespect to the casing, means for preventing endwise movement of therifle bar,

a reciprocatory and non-rotatable valve for distributing pressure fluidto the piston chamber, 50 and clutch members on the rie bar and thevalve intermittently engaging each other to hold the rifle barstationary and thereby cause the piston to describe a partialrevolution.

6. In a fluid actuatedrock drill, the combina- 55 tion of a casinghaving a piston chamber and a reciprocatory piston in the pistonchamber, a rifle bar interlockingly engaging the piston and beingrotatable with respect to the casing, a reciprocatory valve fordistributing pressure uid o0 to the piston chamber and interlockinglyengaging the casing to prevent rotary movement of the valve, and clutchmembers on the rifle bar and the valve intermittently engaging eachother to hold the rie bar stationary and thereby cause the piston todescribe a partial revolution.

'7. In a fluid actuated rock drill, the combination of a casing having apiston chamber and a reciprocatory piston in the piston chamber, a riebar interlockingly engaging the piston and being rotatable with respectto the casing, a reciprocatory valve for distributing pressure fluid tothe piston chamber and being arranged coaxially with the rifle bar,means on the casing interlockingly engaging the valve to prevent rotarymovement of the valve, and clutch members in the adjacent surfaces ofthe valve and the rifle bar intermittently engaging each other to holdthe rifle bar stationary and thereby cause the piston to describe apartial revolution.

8. In a fluid actuated rock drill, the combina.- tion of a casing havinga piston chamber and a reciprocatory piston in the piston chamber, arifle bar interlockingly engaging the piston and being freely rotatableWith respect to the casing, a non-rotatable recprocatory valve fordistributing pressure fluid to the piston chamber and having opposedpressure surfaces, and clutch members in the rifle bar and one pressuresurface intermittently engaging each other to hold the rifle barstationary and thereby cause the piston to describe a partialrevolution.

9. In a uid actuated rock drill, the combination of a casing having apiston chamber and a reciprocatory piston in the piston chamber, a riflebar interlockingly engaging the piston and being freely rotatable withrespect to the casing, a non-rotatable reciprocatory valve fordistributing pressure fluid to the piston chamber and having opposedactuating and holding surfaces, and clutch members in the rie bar andone holding surface intermittently engaging each other to prevent rotarymovement of the rie bar and thereby cause the piston to describe apartial revolution.

FRED M. SLATER.

